1. Field of the Invention
The present invention relates to a hydraulic shock absorber, and more particularly to a hydraulic shock absorber for use as the rear cushion of an off-the-road motorcycle.
2. Description of the Prior Art
In an off-the-road motorcycle, more particularly in a motocross motorcycle, it is desired to change the damping force of the rear cushion under compression in accordance with the road condition or the preference of a driver.
One of the hydraulic shock absorbers made capable of adjusting the damping force under compression is disclosed in and known from Japanese Utility Model Specification No. 54-19890, which was laid open for public inspection on Feb. 8, 1979. This disclosed shock absorber has not been used on motocross motorcycles because the adjustment of the damping force requires the skills of an experienced service man and, additionally, takes a long time.
In the motocross motorcycle or the like, therefore, a plurality of shock absorbers having different damping forces are prepared in advance and are replaced in accordance with the road condition or the preference of the driver. According to this current practice, however, considerable time is wasted in making the replacement.